The present invention is directed to a convertible top or roof for motor vehicles having a linkage system including a front roof frame, a rear roof frame, a main roof arch and a two-part retaining rod supporting the main roof arch against a tension bracket. The two parts or halves of the retaining rod along with the front and rear roof frames are displaced into an extended position by a linkage for placing the top in the extended or closed position and for securing it in that position.
In convertible tops for motor vehicles, it is necessary to lock the interengaged articulated parts of the linkage system in position relative to one another, particularly the parts or sections connected so that they can pivot relative to one another when collapsing or folding the top into the open position. The two parts can be the front roof frame and the rear roof frame, as well as the two interconnected parts of the retaining rod connecting the main roof arch to the tension bracket, whereby such parts are locked relative to one another in the extended position defining the closed position of the collapsible top and such locking is effected in known designs of convertible tops by providing an over dead center position of the articulated interconnected parts along with respective guidance and actuating devices. This known manner of locking interconnected articulated linkage parts of collapsible convertible tops requires a complicated and expensive design of the linkage system for the folding top and is subject to the disadvantage that linkage parts bridging great distances can buckle across the extended position resulting in some instability, particularly in motor-driven convertible tops. Moreover, a stronger design of the drive for the collapsible top is necessary to overcome the required over dead center position of the various combination of parts and this results in a further increase in the over-all cost of the folding top.